SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Function mapFromArrays (children 1)
     ExpressionList (children 2)
      Function array (children 1)
       ExpressionList (children 2)
        Function toLowCardinality (children 1)
         ExpressionList (children 1)
          Function toNullable (children 1)
           ExpressionList (children 1)
            Literal UInt64_1
        Function toLowCardinality (children 1)
         ExpressionList (children 1)
          Function CAST (children 1)
           ExpressionList (children 2)
            Literal NULL
            Literal \'Nullable(Int32)\'
      Literal Array_[UInt64_3, UInt64_4]
   ExpressionList (children 1)
    Literal UInt64_1
